Centrifugal fan or pump.



N. w. AKHVIQFF. CENTRIFUGAL FAN 0R PUMP.

APPLICATION FILED FEB. 21, 1910.

Patnted Bed; 2

2 SHEETSS UNITED STATES QFFTGEO NICHOLAS W. AKIMOFF, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY DIREGT AND MESNE ASSIGNMENTS, T0 AMERICAN BLOWER COMPANY, OF GREEN ISLAND, NEW YORK, A CORPORATION NEW YORK.

onit'rnrroean ran on PUMP.

Specification of Letters Patent.

Patented Dec. 2%, 1915.

Application filed February 21, 1910. Serial No. 545,004L.

To all whom it may concern:

Be it known that I, NICHOLAS WV. AKI- MOFF, a subject of the Czar of Russia, resid-- ing at Philadelphia, in the county of Phila delphia and State of Pennsylvania, have invented certain new and useful Improve ments in Centrifugal Fans or Pumps, of which the following is a specification.

My invention relates to centrifugal fans or pumps and in such connection it relates more particularly to the construction and arrangement of the blades of the rotors of such devices.

The object of my invention is to provide planes radiating from the axis ofrotation but the blades in this instance were inclined throughout their length, resulting in an arrangement of frustoconical conformation. In these twomain types certain deficiencies occur which are readily understood. In the cylindrical form it is evident that the blades will not act uniformly throughout their length on the impelled fluid on account of the differences in direction of said fluid as it is presented to the blades and is taken up and impelled thereby. This deficiency is well known to those skilled in the art. In

the other or conical type of rotor the defect In the device of my present invention ll seek to overcome the defects as before stated by constructing a rotor with non-twisted concaved blades of substantially uniform cross section throughout their length, but which are arranged at an angle both to the axis of rotation of the rotor and to the planes radiating from said axis. This construction results in a rotor having a surface developed by the rotating blades which is neither cylindrical nor conical but on the other hand is a one napped hyperboloid of revolution which it is believed is a con figuration which will present the best condition for the impelled fluid as the same enters the interstices between the blades.

The nature and characteristic features of my inventionwill be more readily under-" stood from the following description taken n connect on with the accompanying drawlngs forming part hereof, in which-- Figure 1 is a side elevation of a rotor of a centrifugal fan or pump embodying the main features of my present invention; Fig. 2 is an end elevation thereof; Fig. 3 is a plane section taken on the line 33 of Fig. 1 and Fig. 4; is a plane section taken on. the line 4.l of Fig. 1.

Referring to the drawings, 5 is the shaft on which the rotor is mounted; 6 is a disk which forms a closure at one end of said rotor, and 7 is a ring at the .other or intake end of the rotor. A

8 are the impelli'ng blades of curvilinear cross section, as clearly shownin Figs. 2 to 4. The blades are preferably of a uni- .form cross section and untwis'ted throughout their length and are secured at one end to the disk 6 and at the other end to the ring 7. The blades extend from disk 6 to ring 7 in a direction at an angle to the axis of the shaft 5 as well as at an angle to the planes radiating from said axis as clearly shown in Fig. l of the drawings. By the construction as aforesaid the inner and outer edges of the blades 8 will each develop in their rotation a surface which will be a true hyperboloid of revolution due to the well known mathematical property of the development of such a surface by the ro tation of a straight line about an axis with which said line is not parallel and which it does not intersect. This arrangement results in several advantages, it being evident that the impelled fluid must enter the central chamber inclosed by theblades 8 in an initial direction parallel to the axis of Totation and that as the direction of the fluid is changed as the same is taken up by the blades the proper angle of the edges said blades considered longitudinally will; be

presented to the impelled fluid at'all points along the length of said blades. F urthermore as clearly shown in Figs. 3 and 4 of the drawings, the angle of incidence of the inner part of each of the blades with respect to the radius will be varied throughout the length of the blades and thereby will be secured a greater degree of efliciency than would otherwise be the case, this result being obtained without complexity of the shape of the individual blades.

While the device as shown only encompasses a small frustum of a hyperboloid of revolution on one side of the transverse axis only of the hyperbola from which the hyperboloid of revolution is generated, it will of course be understood that-any desired frustum of the hyperboloid may be obtained by variations in the length of blades as well as through variations in the angle of, the

generatrix formed by the edges of said blades.

- Having thus described the nature and characteristic features of my invention what I claim as new and desire to secure by Letters Patent is 1 1. A rotor for a centrifugal fan or pump comprising a series of elongated blades arranged in form of a conoidal drum to form a central intake chamber, and adapted to draw in the fluid axially and discharge it circumferentially, and having a disk at the smaller end of the drum, such blades having their disk ends inclined in the direction ofrotation to a greater extent than their intake ends.

2. A rotor for centrifugal fa-ns'or pumps comprising a series of elongated blades arranged in drum form to form a central intake chamber, and adapted to draw in the t.

fluid axially and discharge it circumferentially, and each of said blades being arranged with its longitudinal extension inclined to all planes radiating from the axis of rotation and having its disk end inclined in the direction ofrotation to a greater extent than its intake end.

3. A rotor for centrifugal fans or pumps comprising a disk forming-a closure at one end, a ring at the other or intake end, and a series of elongated blades concaved in transverse section and each extending from said disk to said ring in a direction inclined to all planes radiating from the axis of rotation, and the disk ends of said blades being inclined in the direction of rotation to a greater extent than their intake ends.

4. A rotor for centrifugal fans or pumps comprising a disk forming a closure at one end, a ring at the other or intake end, and a series of elongated blades concaved in transverse section and each extending from said disk to said ring in a direction inclined to all planes radiating from the axis of rotation, said blades being ofsubstantially uni form cross-section and untwisted throughout their length whereby the disk ends of said blades will be inclined in the direction of rotation to a greater extent than their intake ends.

5. A rotor for centrifugal fans or pumps comprising a series of elongated blades arranged in drum form to form a central chamber, and adaptedto draw in the fluid axially and discharge it circumferentially,

such blades having their disk ends inclined in the direction of rotation to a greater extent than their intake ends and' having straight inner and outer marginal edges extending in a direction inclined-to all planes radiating from the axis of rotation to thereby he in surfaces Whichare hyperboloids of revolution.

6. A rotor for a centrifugal fan or pump comprising a series of elongated blades arranged in form of a conoidal drum to form a central intake chamber, and adapted to draw in the fluid axially and discharge it circumferentially, the blades being curved with their concave faces in advance, and the blades inclined to planes coinciding with the 8. A rotor for a centrifugal fan or pump comprising a series of elongated curved blades arranged in form of a conoidal drum to form a central intake chamber, and adapted to draw in the fluid axially and discharge it circu'mferentially, the blades being inclined to planes coinciding with the axis of. rotation, and being arranged in transverse section with respect to radii from the axis of rotation, sothat each blade presents from. the smaller to the larger end of the drum .a continually changing angle to a radius intersecting it. v

9. A rotor for a centrifugal fan or pump comprising a series of elongated blades arranged in form of a conoidal drum to form a central intake chamber, and'adapted to draw in the fluid axially and discharge it circum ferentially, the blades being inclined toplanes coinciding with the axis of rotation,

and being arranged in transverse section with respect to radii from the axis of rotation, so that each blade has its tip portion at the smaller end of the drum inclined for- Wardly of a radius intersecting it and inclined thence backwardly toward the larger end of the drum.

1 0. A rotor for a centrifugal fan or pump comprising a series of elongated blades arranged in form of a conoidal drum to form a central intake chamber, and adapted to draw in the fluid axially and discharge it circumferentially, the blades being inclined to planes coinciding with the axis of rotation,

and in transverse section shaped to afiord the more efi'ectlve centrifugal ant-ion at the smaller end of the drum and the less effective centrifugal action at the larger end of the drum.

In testimony whereof l have hereunto signed my name in the presence of two Wit- 

